From: Chanho Min <chanho.min@lge.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Kyungsik Lee <kyungsik.lee@lge.com>,
Yann Collet <yann.collet.73@gmail.com>,
Bob Pearson <rpearson@systemfabricworks.com>,
Richard Weinberger <richard@nod.at>,
Geert Uytterhoeven <geert.uytterhoeven@gmail.com>,
linux-kernel@vger.kernel.org, sparclinux@vger.kernel.org,
linux-m68k@vger.kernel.org, linux-next@vger.kernel.org,
Chanho Min <chanho.min@lge.com>
Subject: [PATCH] lib: add weak __clzsi2()/__clzdi2() functions
Date: Mon, 29 Apr 2013 14:40:05 +0900 [thread overview]
Message-ID: <1367214005-14302-1-git-send-email-chanho.min@lge.com> (raw)
Some architectures need __clzsi2() or __clzdi2() for __builtin_clz and
It causes build failure. They can be implemented using the fls() and
overridden by linking arch-specific versions may not be implemented yet.
Reference: https://lkml.org/lkml/2013/4/18/603
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Chanho Min <chanho.min@lge.com>
---
lib/Makefile | 2 +-
lib/clz.c | 36 ++++++++++++++++++++++++++++++++++++
2 files changed, 37 insertions(+), 1 deletion(-)
create mode 100644 lib/clz.c
diff --git a/lib/Makefile b/lib/Makefile
index af79e8c..e17b3ee 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -23,7 +23,7 @@ lib-y += kobject.o klist.o
obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \
bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o \
- gcd.o lcm.o list_sort.o uuid.o flex_array.o \
+ gcd.o lcm.o list_sort.o uuid.o flex_array.o clz.o\
bsearch.o find_last_bit.o find_next_bit.o llist.o memweight.o kfifo.o
obj-y += string_helpers.o
obj-$(CONFIG_TEST_STRING_HELPERS) += test-string_helpers.o
diff --git a/lib/clz.c b/lib/clz.c
new file mode 100644
index 0000000..5222b2d
--- /dev/null
+++ b/lib/clz.c
@@ -0,0 +1,36 @@
+/*
+ * lib/clz.c
+ *
+ * Copyright (C) 2013 Chanho Min <chanho.min@lge.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * __clzsi2/_clzdi2() can be overridden by linking arch-specific versions.
+ */
+
+#include <linux/export.h>
+#include <linux/kernel.h>
+
+int __weak __clzsi2(int val)
+{
+ return BITS_PER_LONG - fls(val);
+}
+EXPORT_SYMBOL(__clzsi2);
+
+#if BITS_PER_LONG == 32
+int __weak __clzdi2(long val)
+{
+ return BITS_PER_LONG - fls((int)val);
+}
+EXPORT_SYMBOL(__clzdi2);
+#elif BITS_PER_LONG == 64
+int __weak __clzdi2i(long val)
+{
+ return BITS_PER_LONG - fls64((u64)val);
+}
+EXPORT_SYMBOL(__clzdi2);
+#else
+#error BITS_PER_LONG not 32 or 64
+#endif
--
1.7.9.5
next reply other threads:[~2013-04-29 5:40 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-29 5:40 Chanho Min [this message]
2013-04-29 7:20 ` [PATCH] lib: add weak __clzsi2()/__clzdi2() functions Geert Uytterhoeven
2013-04-30 21:46 ` Andrew Morton
2013-05-01 7:35 ` Geert Uytterhoeven
2013-05-02 0:58 ` 민찬호
2013-04-30 19:47 ` Andrew Morton
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1367214005-14302-1-git-send-email-chanho.min@lge.com \
--to=chanho.min@lge.com \
--cc=akpm@linux-foundation.org \
--cc=geert.uytterhoeven@gmail.com \
--cc=kyungsik.lee@lge.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-m68k@vger.kernel.org \
--cc=linux-next@vger.kernel.org \
--cc=richard@nod.at \
--cc=rpearson@systemfabricworks.com \
--cc=sparclinux@vger.kernel.org \
--cc=yann.collet.73@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).